From c54a744cff8917f50a698212cba5a0bfeac1e31d Mon Sep 17 00:00:00 2001
From: Andreea Pavel <apavel@mozilla.com>
Date: Sat, 9 Mar 2019 22:34:50 +0200
Subject: [PATCH] Backed out changeset 5bc7479ef4a1 (bug 1532502) for very
 frequent win asan failures with exit code 1

--HG--
extra : rebase_source : 636c7036385ef42ec755c78d86eb34799d2e0bcb
extra : amend_source : ec830eafb0ef96dad8229f078ce27166ab9ef876
---
 build/build-clang/clang-win64.json            |  2 +-
 ...4836-unpoison-thread-stacks-callback.patch | 34 -------------------
 .../build-clang/unpoison-thread-stacks.patch  | 34 +++++++++++++++++++
 3 files changed, 35 insertions(+), 35 deletions(-)
 delete mode 100644 build/build-clang/r354836-unpoison-thread-stacks-callback.patch
 create mode 100644 build/build-clang/unpoison-thread-stacks.patch

diff --git a/build/build-clang/clang-win64.json b/build/build-clang/clang-win64.json
index a7184099959c..039c58a75296 100644
--- a/build/build-clang/clang-win64.json
+++ b/build/build-clang/clang-win64.json
@@ -15,7 +15,7 @@
     "ml": "ml64.exe",
     "patches": [
       "workaround-issue38586.patch",
-      "r354836-unpoison-thread-stacks-callback.patch",
+      "unpoison-thread-stacks.patch",
       "downgrade-mangling-error.patch",
       "loosen-msvc-detection.patch"
     ]
diff --git a/build/build-clang/r354836-unpoison-thread-stacks-callback.patch b/build/build-clang/r354836-unpoison-thread-stacks-callback.patch
deleted file mode 100644
index a874ea8a8f6b..000000000000
--- a/build/build-clang/r354836-unpoison-thread-stacks-callback.patch
+++ /dev/null
@@ -1,34 +0,0 @@
-[winasan] Unpoison stack memory when threads exit (redux)
-
-This is a second attempt at r342652 using a TLS callback instead of an
-interceptor.
-
-In long-running builds we've seen some ASan complaints during thread creation
-that we suspect are due to leftover poisoning from previous threads whose
-stacks occupied that memory. This patch adds a callback that unpoisons the
-stack memory when a thread exits.
-
-Differential Revision: https://reviews.llvm.org/D58641
-
---- a/compiler-rt/lib/asan/asan_win.cc
-+++ b/compiler-rt/lib/asan/asan_win.cc
-@@ -354,6 +354,19 @@
-     unsigned long, void *) = asan_thread_init;
- #endif
- 
-+static void NTAPI asan_thread_exit(void *module, DWORD reason, void *reserved) {
-+  if (reason == DLL_THREAD_DETACH) {
-+    // Unpoison the thread's stack because the memory may be re-used.
-+    NT_TIB *tib = (NT_TIB *)NtCurrentTeb();
-+    uptr stackSize = (uptr)tib->StackBase - (uptr)tib->StackLimit;
-+    __asan_unpoison_memory_region(tib->StackLimit, stackSize);
-+  }
-+}
-+
-+#pragma section(".CRT$XLY", long, read)  // NOLINT
-+__declspec(allocate(".CRT$XLY")) void (NTAPI *__asan_tls_exit)(void *,
-+    unsigned long, void *) = asan_thread_exit;
-+
- WIN_FORCE_LINK(__asan_dso_reg_hook)
- 
- // }}}
diff --git a/build/build-clang/unpoison-thread-stacks.patch b/build/build-clang/unpoison-thread-stacks.patch
new file mode 100644
index 000000000000..375732b91d2f
--- /dev/null
+++ b/build/build-clang/unpoison-thread-stacks.patch
@@ -0,0 +1,34 @@
+[winasan] Unpoison the stack in NtTerminateThread
+
+In long-running builds we've seen some ASan complaints during thread creation that we suspect are due to leftover poisoning from previous threads whose stacks occupied that memory. This patch adds a hook that unpoisons the stack just before the NtTerminateThread syscall.
+
+Differential Revision: https://reviews.llvm.org/D52091
+
+--- a/compiler-rt/lib/asan/asan_win.cc	(revision 342651)
++++ b/compiler-rt/lib/asan/asan_win.cc	(revision 342652)
+@@ -154,6 +154,14 @@
+                             asan_thread_start, t, thr_flags, tid);
+ }
+ 
++INTERCEPTOR_WINAPI(void, NtTerminateThread, void *rcx) {
++  // Unpoison the terminating thread's stack because the memory may be re-used.
++  NT_TIB *tib = (NT_TIB *)NtCurrentTeb();
++  uptr stackSize = (uptr)tib->StackBase - (uptr)tib->StackLimit;
++  __asan_unpoison_memory_region(tib->StackLimit, stackSize);
++  return REAL(NtTerminateThread(rcx));
++}
++
+ // }}}
+ 
+ namespace __asan {
+@@ -169,7 +177,9 @@
+ 
+   ASAN_INTERCEPT_FUNC(CreateThread);
+   ASAN_INTERCEPT_FUNC(SetUnhandledExceptionFilter);
+-
++  CHECK(::__interception::OverrideFunction("NtTerminateThread",
++                                           (uptr)WRAP(NtTerminateThread),
++                                           (uptr *)&REAL(NtTerminateThread)));
+ #ifdef _WIN64
+   ASAN_INTERCEPT_FUNC(__C_specific_handler);
+ #else